A study of children being admitted to the Royal Cornwall Hospital has shown that significant numbers had been drinking.
A National Health Service report said 62 children in a 20-month period were given blood tests in hospital which proved they were intoxicated.
The report, by the director of public health medicine for central Cornwall, said the full scale of the problem of drinking among children under 16 may be hidden.
Many children are not brought into hospital and not all those admitted were given blood tests.
Holiday injuries
In the study, almost half the children who were assessed said they drank during the week.
The report also found that about 60% of children who were admitted to the hospital at Treliske with injuries were on holiday.
Many were suffering from sunburn or falls.
More than 13,000 episodes of injuries or poisoning among under 16s were logged during the survey.
Boys accounted for more than 60% of injuries.
The information is being used to develop programmes to cut accident rates.